Faith comes by hearing the preaching of God's word as demonstrated in Acts 2:14-41. Hopefully the below will help you understand the Baptism of Christ and His salvation.
Lev 16:23 And Aaron shall come into the tabernacle of the congregation, and shall put off the linen garments, which he put on when he went into the holy place, and shall leave them there:
Lev 16:24 And he shall wash his flesh with water in the holy place, and put on his garments, and come forth, and offer his burnt offering, and the burnt offering of the people, and make an atonement for himself, and for the people.
The Mikveh (meaning a collection of water) in the OT was a bath used for the purpose of ritual immersion. Several biblical regulations specify that full immersion in water is required to regain ritual purity after ritually impure incidents have occured. In Priestly law, the ultimate purpose of ritual purification was to protect God's sanctuary, the tabernacle, from contamination, Leviticus chapter 15.
The Mikveh, being a shadow of John's baptism and the baptism of the Holy Spirit, was for purification, not for remission of sin, like that of what Esaias prophecied saying, The voice of one crying in the wilderness, Prepare ye the way of the Lord, make his paths straight, Isaiah 40:3. In those days came John the Baptist, preaching in the wilderness of Judaea, And saying, Repent ye: for the kingdom of heaven is at hand. And were baptized of him in Jordan, confessing their sins, Matthew 3:1-6. John said, I indeed baptize you with water unto repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost, and with fire, Matthew 3:11.
Ephesians 2:8 Salvation is by grace through faith in Jesus and not by works, which would make water baptism a work towards repentance. John said I must decrease and Jesus increase. John's water baptism was only for repentance as being prepared for the coming of the Lord as the water represented the washing away of sin, or as John put it "prepare ye the way of the Lord". It is not clear in scripture that Jesus ever baptized anyone in water even though He first came to John's water baptism as a fulfillment of prophecy as He had to identify with humanity even though He had no sin. This was the beginning of Christ ministry as the Holy Spirit fell down on Him that day as God gave Him full power and authority here on earth and there after Jesus went about teaching the disciples as it was not Jesus who the Pharisees heard that He baptized more than John did, John 4:1-3 but His disciples baptizing others in water for remission of sin after the death of John the Baptist as all together they would have baptized others in water for the remission of sin then John could at one time. Jesus could not baptize anyone in the Holy Spirit until the day of Pentecost after He ascended up to the Father and the Father sent down the indwelling Holy Spirit, Acts 2.
John 3:5 never mentions the word baptize, but says only by being born of water and spirit, which means water as living water, word of God, that no one can enter into the kingdom of God unless they are Spiritually renewed (born again) by the hearing of the word, which is Christ Jesus and by the Holy Spirit that came on them in the OT and indwells us in the NT. Many do read into the passage a preconceived idea or theology, but baptism is never mentioned in this verse. God's word is living water as described in John 4:4-26; 7:37-39; 12:44-50; Ephesians 5:26; 1 John 5:5-8; Jeremiah 17:13; Zechariah 14:8, 9; Rev 21:6-8; Ezekiel 47:22.
If salvation came by actual immersion in water Jesus clearly could have simply stated, "Truly, truly, I say to you, unless one is baptized by being immersed in water and born of the Spirit, he cannot enter into the kingdom of God.” Further, if Jesus had made such a statement, He would have contradicted numerous other Bible passages that make it clear that salvation is by faith (John 3:16; John 3:36; Ephesians 2:8-9; Titus 3:5).
There is the case of the thief on the cross who repented, the women who was to be stoned for adultery, the women at the well, death bed confessions and even those who are incapacitated that can not be immersed in water. Does this mean they are not saved or born again, no. It means that no dirty river water is going to save anyone, but that it is only a symbol of repentance like that of John the baptist who called those to repent first. There is nothing wrong with being dunked in water, but know that it is only an outward appearance to others of what has already taken place Spiritually within you when you repented, accepted Jesus and was indwelled with the Holy Spirit.
Baptism is not mentioned in John chapter three so why do so many believe we are to be dunked in dirty river water as the water can not bring about Gods salvation, but only by faith do we believe as it comes by Gods grace, Ephesians 2:1-10, as we hear the gospel (word/living water) preached to us.
This is what the Jerusalem Bible says:
John 3:3 "I tell you most solemnly, unless a man is born from above, he can not see the kingdom of God."
John 3:5-7 "I tell you most solemnly, unless a man is born through water and the Spirit, he can not enter the kingdom of God. What is born of the flesh is flesh,(sin nature) what is born of the Spirit is spirit. Do not be surprised when I say you must be born from above.
One needs to hear the word of God, as word being living water, in order to know they have to be born again of the Spirit in order to see and enter the kingdom of God.
John's baptism was literal, but yet symbolic for cleansing after one repented of their sin. Notice in Mark 1:8 I have baptized you with (actual) water, but he (Jesus) will baptize you with the Holy Spirit. (Not water, but baptize you with the Holy Spirit after you have repented and made clean again through the washing of the word as you become a new creation in Christ.
Jesus never baptized anyone in literal water that we know of and also instructed the Disciples to wait upon the indwelling of the Holy Spirit, Acts chapter 1, and then commissioned them to go out preaching the Gospel (word/living water) and to baptize in the name of the Father, Son and Holy Spirit, Matthew 28:16-20.
Being born from above means being born from the heavenly word of God, not dirty river water. When Jesus was baptized by John it was for the fulfillment of Messiah come as the Holy Spirit fell down on Him. Jesus had no need of being baptized in water for the remission of sin.
